Audio 3:13
UWA to look into shark deterrance at beaches

David WeberUpdated
Fri Dec 07 19:55:00 EST 2012

Bubble curtains, strobe lights and underwater sounds may be used in the future to deter sharks from Western Australia's beaches. The WA Government has awarded funding to several projects looking into ways to steer sharks away from beaches, in the wake of a series of fatal attacks.

Transcript

MARK COLVIN: Western Australia may use bubble curtains, strobe lights and underwater sounds in future to deter sharks from the state's beaches.

The WA Government has awarded funding to several projects looking into ways to steer sharks away.

The state has seen five fatal attacks in the space of a year. Already this summer, there's been increased shark activity off Perth beaches.

The University of Western Australia's Oceans Institute has been given funding to test existing shark deterrents.

It's also going to look into developing new ones.

Professor Shaun Collin spoke to David Weber and told him firstly about bubble curtains.

SHAUN COLLIN: Bubbles as in a row of bubbles that would be emanating from say a pipe of some kind that might be placed on the bottom would produce a row of bubbles, whether they be small or large bubbles and that could be controlled.

What the bubbles do is it actually interferes with two of the known senses of sharks; this is their hearing, because they produce low frequency disturbances which can be picked up by the inner ear of the shark, but they also disturb the fine hair cells within their lateral line system and this is a system that detects very small water movements over the body and the head.

DAVID WEBER: Under water strobe lights; there must be some evidence then that strobe lights act as a deterrent?

SHAUN COLLIN: There's not a great deal of evidence yet but we do know quite a lot about the visual system of sharks now through our work over the last 20 years or so. So we understand their acuity, whether they react to colour and not but we also know that, like most animals, including us, that very high intensity light, strobed or otherwise, is rather uncomfortable and can provide almost blinding results which can change behaviour, our behaviour and obviously animals as well.

So, using that as an approach, we intend to look at producing high intensity strobe light, not to be used all the time, but really combine that with some sonar or sensory technology which can actually detect the presence of a shark and then initiate these different sensory stimuli, including light, to deter them from particular areas.

DAVID WEBER: And using sub-aquatic sounds, is there any evidence that certain sounds, perhaps some kind of sonar activity can repel sharks?

SHAUN COLLIN: This is sort of an area which hasn't been explored almost at all. There's only a few scientific studies about the hearing abilities of sharks. We're in fact the only group working at this currently in the world and what we're interested in is what frequency range and intensity range sharks of various species can hear.

So we have set-ups within the laboratory to test the hearing capabilities of a whole range of species and then, based on that knowledge, we can then develop a sound of various intensities and frequency that we know that they can respond to but then is uncomfortable to them and will change their behaviour.